The present invention relates to a chain and in particular to a chain having an outboard roller of the kind that is used to support the chain on guide rails or tracks.
Chains of the kind referred to above are used for many purposes such as to support parts of a moving platform, conveyor or escalator.
The construction of such a chain is broadly similar to the conventional roller chain having inner and outer link plates interconnected by pins that pass through aligned apertures therein. A central roller is disposed on each pin between opposed pairs of inner link plates. The outer link plates are fixed relative to the pin by means of an interference fit and the inner link plates articulate relative to the pin as they are assembled thereto with a clearance fit. The pins each extend laterally outboard of the outer link plates and each end supports a rotary outboard roller. In use, the outboard rollers are in rolling contact with guide rails or tracks disposed on one or both sides for the chain.
Lubrication or maintenance of the bearing surface between the articulating inner link plates and the pin is difficult as access is restricted by the presence of the outboard roller and the elements which the chain is supporting.